*This product is suitable for demonstration experiments on recoil movement in high school physics teaching *Products are mainly composed of adjusting nails, upper and lower supports, water containers, nozzles, bases, beams, columns, sealing seats, supporting seats, etc. *Take out the water container with the mouth facing upward. Install the water container on the bracket and adjust the adjusting screw so that the water container can rotate flexibly. *Pour water into the water container to close to the upper mouth, and put the instrument in the sink. *Water is sprayed out through two symmetrical nozzles. Due to the recoil effect of the water flow, the water container will recoil in the opposite direction of the water flow, and the water container will rotate.